You Tube won't play from Notification Edge

We're all familiar with the notification edge on the right side of our screen. Swipe two fingers from the edge and see the notifications. I get YouTube recommended video suggestions. But, when I click on the suggested video, nothing happens. The video does not play but the notifications get removed as if they did play. Every other notification (such as a received email) opens the correct app and does what's it's supposed to do. It's only YouTube that is not working. I've combed through all the notification settings, can't see anything out of order.

Any suggestions?